1. Field of the Invention
This invention relates to an arrangement for semiconductor power components used in electricity supply installations, and more particularly to an installation with at least one semiconductor power component placed between contact pieces and enclosed in a housing which has an insulator and connecting pieces.
2. Description of the Prior Art
Such installations with thyristors and diodes as active power components are used extensively in electricity supply installations. Because the modern trend is to use semiconductor power components with correspondingly enlarged dimensions in order to control the constantly increasing currents and voltages, it has already been proposed to enclose the components in a 3 inch.times.1 inch sized "press pack" standard housing. Due to the very large constant currents (1,000 to 3,000 A), however it is necessary to provide for the protection of the installation safety devices which exhibit a very high reaction current and consequently a high explosion integral. For the most modern installations at present the value of this explosion integral for a sinusoidal current is EQU .intg.i.sup.2 dt=I.sup.2 /2T/2
where T/2=pulse time, I=mean current intensity, for sinusoidal impulses of approximately 35.multidot.10.sup.6 A.sup.2 sec. (this value corresponds e.g. to a pulse of 83.7 kA/10 msec). But installations in "press pack" standard housings exhibit an explosion integral of only approx. 1.5.multidot.10.sup.6 A.sup.2 sec., which is only a fraction of the value demanded in the most modern existing installations. This value of the explosion integral is attained or exceeded very rapidly, and in particular when a short-circuit current flows in the reverse direction of power components, so that the arc which then develops causes the installation to explode.